Cooled piston rod for double acting engines



June 27, 1933. H. BECKER COOLED PISTON ROD FOR DOUBLE ACTING ENGINES Filed Sept; 16. 1931 Patented June 27, 1933 I UNITED STATES PATENT OFFICE HEINRICH BECKER, 0F AUGSBURG, GERMANY, ASSIGNOR '10 MASCHINENFABRIK AUGSBURG-NURNBERG A. G., OF AUGSBURG, GERMANY, A CORPORATION OF GER- MANY COOLED PISTON ROD FOR DOUBLE ACTING ENGINES Application filed September 16, 1931, Serial No.

This invention relates to internal combustion engines and more particularly to engines in which the pistons are supplied with a cooling medium.

One object of the invention is the provision of a cooled piston rod adapted for use. in internal combustion engines of the double acting type, or the like, in which the piston rod is provided with passages for supplying cooling medium to and from the piston, an outer enclosing tube providing an additional cooling medium passage, for effectively cooling the piston rod While avoiding the danger of excessive material stresses due to excessive differences in temperature of diiferent parts of the piston rod.

Another object of the invention is the provision of a piston rod having a cooling water supply for cooling the piston, and having a lubricating oil passage which cools the outer surface of the piston rod and avoids danger of excessive material stresses.

Other objects and advantages of the invention will be apparent from the following description, the appended claims, and the accompanying drawing.

In the drawing,

Fig. 1 is a side elevational view, partly in section, of a part'of an internal combustion engine embodying the present invention, and

Fig. 2 is a horizontal section on the line 2-2 of Fig. 1.

Referring to the drawing more particularly by reference letters, a designates the piston rod of an internal combustion engine, the invention being herein disclosed as adaptable to a double acting, two stroke engine of the Diesel type, in which it is particularly advantageous, although it may be utilized generally in double acting engines or the like. This piston rod is adapted'to provide for a flow of cooling medium, preferably Water, to the interior of the'piston, and also a return flow fromthe piston. As herein shown, the piston rod a is provided with a longitudinal or axial passage 1) which contains a pipe 0. Cooling water is supplied through the outer passage provided between the pipe 0 and the passage 6, this annular passage communicating with the interior of the piston at one and communi- 563,145, and in Germany September 23, 1930.

eating at its other end with a pipe e leading from the crosshead to the coling water coils g. The return flow of the cooling water takes place from the interior chamber of the piston,

through the central passage, that is through i the pipe 0, through the crosshead and the pipe f connected thereto and then to the inlet side of the cooling coils g.

Surrounding or enclosing the piston rod a is a pipe or tube It, the upper end of which is fastened to the piston and the lower end of which is secured to the crosshead. Between the inner side of the pipe it and the outer side of the piston rod a are ribs h, preferably provided spirally on the inner side of the tube IL so as to provide both inlet and outlet passages for the flow of cooling medium on the outer side of the piston rod. These ribs provide channels 2', which at one end are connected with a pipe j through which a supply of engine. lubricating oil is forced from the oil pump or other oil supply means of the engine. The outlet passage formed by the ribs mentioned k leads to the outlet pipe which extends to the crankcase of the engine. The ribs h are displaced 180 apart as shown in the sectional view so that it will be apparent that one spiral passage communicates other passage communicates at its .lower end with the outlet pipe, both passages being in communication with one another at their upper ends by reason of the enlarged passage as shown in Fig. 1. It Will thus be apparent that a constant flow of the lubricating oil of the engine is forced through the pipe j and along and around the outer side of the piston rod so as to cool the outside surface of the piston rod and prevent excessive material stresses and strains by preventing unusual or excessive difierences in temperature of the various parts of the piston rod. An effective inside cooling of the piston rod is obtained by the cooling water that flows to and from the piston and at the same time the outer portions of the piston rod are effectively cooled by the other cooling medium supply, which as herein disclosed is a flow of lubricating oil. This sions in the metal by partly equalizing the temperature of the interior of the piston rod with its exterior, also prevents the outside of the piston rod from corroding. The outside of the piston rod, in an engine of this character, would otherwise be subjected to excessively high temperature due to its contact with very hot burning gases having the effect of creating excessively great strains in the metal with the resulting likelihood of fractures.

While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. In a combustion engine of the character described, a piston rod having passages for supplying cooling medium to and from the piston, and an enclosing tube providing an additional cooling medium passage for cooling the outside of the piston rod.

2. In a combustion en ine of the character described, a piston rod aving passages for supplying cooling medium to and from the piston, and an enclosing tube providing with the outer side of the piston rod both inlet and outlet passages for additional cooling meidium which cools the outsideof the piston ro 3 In a combustion engine of the character described having a combustion chamber, a piston rod extending through said combustion chamber, and means enclosing said piston rod and providing parallel inlet and outlet passages between its inner surface and the outer surface of the piston rod for the inlet and outlet flow of cooling medium.

4. In a combustion engine of the character described, a piston rod having interior passages for supplying cooling medium to and from the piston, and means enclosing said piston rod and providing therewith an 011 passage, and means connectin said oil passage to the lubricating oil supp y of said engme.

5. In a combustion engine of the character descrlbed, a piston rod having interior passages for thesupply of coolin medium to and from the piston, and an enc osing tube surrounding the piston rod and providing interior passages between its inner surface and the outer surface of the piston rod for the lnlet and outlet flow of cooling medium.

6. In a combustion engine of the character described, a piston, a piston rod having intenor passages for the supply of cooling medlum to and from the piston, and an enclosing tube surrounding the piston rod and providing interior passages between its inner surface and the outer surface of the piston rod for the inlet and outlet flow of lubricat ing oil, means connecting one of said lubr cating oil passages to the lubricating o1l supply, and means connecting the other lubricating oil passage to the engine crankcase.

7. A cooled piston rod for double acting engines of the character described, comprising a rod having concentric cooling water passages leading to and from the piston, and an enclosing tube having interior ribs providing inlet and outlet oil passages on the outer side of the piston rod adapted to be connected to the engine lubricating oil supply and the engine crankcase respectively.

8. In a combustion engine of the character described having a combustion chamber, a piston rod member extending through said combustion chamber, and an enclosing member enclosing said piston rod member, one of said members having spiral ribs extending to the adjacent surface of the other member and providing two spiral passages along the outer side of the piston rod member for the inlet and outlet flow of coolin medium.

In testimony whereof faifix my si nature.

HEINRICH BEG ER. 

